Dado-cutter.



No. 829,927. PATENTED AUG. 28, 1906. B. G. LUTHER.

' DADO CUTTER.

APPLICATION FILED IEBJB. 1906.

M r-N55555: Q M NY 'f il WATT! UNITED STATES PATEN T OFFICE.

DADO-CUTTER.

Specification of Letters Patent.

Patented Aug. 28, 1906.

Application filed February 5, 1906. Serial No. 299,633.

To all whom it may concern.-

Be it known that I, BENJAMIN G. LUTHER, a citizen of the United States,residing at Worcester, in the county of Worcester and State ofMassachusetts, have invented a new and useful Improvement inDado-Cutters, of which the following is a specification.

My invention consists in the improved construction of the dado-cutter,whereby the full practical strength of the board at the dadogrooves maybe maintained.

In the accompanying drawings, Figure 1 represents a side view of myimproved dadocutter. Fig. 2 represents a section taken in the line 2 2of Fig. 1. Fig.3 represents a section of a piece of board provided withopposite dado-grooves produced by means of a dado-cutter constructed asshown in Figs. 1 and 2. Fig. 4 represents the same when the edges of theboard partitions are placed in the dado-grooves.

In the drawings, A represents a dado-cutter of full size formed in onepiece, the cutting-teeth a a of which are backed off, as indicated bythe circumferential dotted line as a: of Fig. 1, and provided withV-shaped grooves b b at their opposite edges, as shown in Fig. 2,whereby a smooth out will be made at the parallel edges of thedado-groove, and at the same time the maximum degree of strength may bepreserved in the grooved board, since the scoring ed es 0 c of thecutter do not need to project beIow the intermediate cutting- When theedges 6 e of the boards D D are inserted into the grooves C C, theridges f f will be reduced in their elevation, as shown in Fig. 4, so asto produce a proper closed joint between the bottom of the dado-groovesand the inserted edges of the boards D D, the height of the said ridgesbeing in practice very slight.

In the operation of the ordinary dado-head the grooved board B isweakened by the action of the'proj ecting scoring-cutters arranged atthe opposite sides of the said head, where as in my invention a smoothgroove may be formed without requiring the use of the projectingscoring-cutters I claim as my invention A dado-cutter having theopposite edges of its cutting-teeth provided with grooves which serve toproduce the scoring edges of the cutter.

BENJAMIN G. LUTHER.

Witnesses:

SOCRATES SoHoLFIELD, JOHN MITCHELL.

